Economic productivity has declined in some countries as a result of:

1.the bubonic plague
2.an outbreak of sars
3.an ebola outbreak
4.the aids pandemic

in all honesty, it really hasn't. except that hitler killed himself.

in the 1800s, chinese workers migrated to the united states, first to work in the gold mines, but also to take agricultural jobs, and factory work, especially in the garment industry. chinese immigrants were particularly instrumental in building railroads in the american west, and as chinese laborers grew successful in the united states, a number of them became entrepreneurs in their own right. as the numbers of chinese laborers increased, so did the strength of anti-chinese sentiment among other workers in the american economy. this finally resulted in legislation that aimed to limit future immigration of chinese workers to the united states, and threatened to sour diplomatic relations between the united states and china.

southern north america: yucatán peninsula in southern mexico extending into northern guatemala, and northern belize. these moist forests on the yucatán peninsula of south-eastern mexico are characterized by a tropical humid climate with little topographic relief.

explanation: